A coalition of file-sharing sites are voluntarily taking themselves offline to protest against the likely passing of new legislation tomorrow. The sites, which together are believed to generate up to 70% of Spain's Internet traffic, will display a black page warning that if the so-called Sinde Act is approved, their sites could disappear forever. Earlier this month, cables leaked by Wikileaks showed that Spain had bowed to US pressure to introduce the law.

In recent times, Spanish courts have ruled repeatedly that subject to some fairly minor conditions, operating a file-sharing site falls within the boundaries of the law.

However, as shown by diplomatic cables recently leaked by Wikileaks, under pressure from the United States, the Spanish Government proposed new legislation to close loopholes and provide sweeping new anti-filesharing powers.

The Sustainable Economy Law (LES) is likely to be approved in Spain tomorrow and is expected to pose a real problem to file-sharing sites. The legislation, popularly known as the Sinde Act in reference to its main driving force Minister of Culture Ángeles González-Sinde, has been widely protested but could be fully adopted as early as February next year.

The law will provides for the creation of a Commission on Intellectual Property under the Ministry of Culture. It would have the power to deal with complaints against websites that link to copyright movies, music and software, including blocking and taking them offline.

The opposition to the passing of the legislation is growing, not least due to the decision by Congress to approve the Sustainable Economy Law in a single meeting. Although the bill will pass to the Senate, Congress will be able to ignore any amendments introduced there.

In response, many of Spain’s largest file-sharing sites will be protesting today by voluntarily taking themselves offline. Each will display the message shown below (translated from Spanish) and link to anti-censorship website No al Cierre de Webs.

The list of sites includes Cinetube, DivxTotal, Mydescarga, Peliculasyonkis, Series Danko, Seriespepito, Seriesyonkis and SuBTorrents.

It is believed that in total the sites, which have millions of pageviews, help to generate up to 70% of Spain’s Internet traffic. However, the new law could take them offline very quickly indeed.

Following complaints by rightsholders to the Commission on Intellectual Property, site status would be reviewed by a court which would then be required to take action within 4 days.